First off non of us are trained to give a medical opinion. That being said I can only give you an opinion.
You really haven't given us enough info. First off how old are you. Age affects ED.You may want to consider seeing your doctor.
But my guess is this is not physical but more mental. If you have engaged in a lot of sex involving anal stimulation your body will only want to react that way.

Well I certainly (and I guess no one here) can NOT tell you if you've caused you any harm over the years, that truly depends on what you have been doing.

However, just from wearing & using diapers, erectile dysfunction certainly can NOT occur. What can happen, during the time you wear diapers is that your SPERM COUNT decreases, as you increase the temperature around this area - but it's fully "reversible" and also has NO IMPACT on erection at any rate.

Anal activities will usually massage the prostate and that in tern is a highly "sensible" area and not falsely sometimes labeled as the "male G-Spot" (or P-Spot).
If you like it, it will most likely give you more than the "normal" pleasure... and thus maybe help to facilitate an erection in the first place.

ED of any kind is often also a psychological matter - I mean, well, if you can get and maintain an erection by getting pleasured through the backdoor, it means that mechanically most likely everything is quite with the penis and it's ability to get erect.
So it can be a psychological thing - maybe you simply don't get triggered by what caused you to get aroused before?

I wouldn't go so far as to say that none of us can give medical advice, there might be a doctor on here somewhere xD lol

but my personal opinion is pretty much what everyone else has said, though from the point of discussion regarding your anal activity, i can tell you right now that there is nothing in your aal cavity that you could have damaged that would have led to ED. If you are saying that you only get an erection when involved in diaper and anal play, then its psychological and you have should consider maybe changing it up or toning it down and trying to ween yourself off it.

I wouldn't go so far as to say that none of us can give medical advice, there might be a doctor on here somewhere xD lol

Emily,

Now even if theres a doc on here, if he or she is any bit professional he/she would never make an assessment of a medical matter online.
No doc, no matter how good could make any diagnosis from the input given and without really diagnosing the patient in person.
they might "guess" but would know better than to throw diagnosis out over the web ...

The initial "guess" is what I'm implying. I'm not saying give a full diagnosis but still there's no harm in a professional "opinion". And it was more meant to be a humorous comment not to be taken seriously, I was just pointing out that it's silly to assume no one here is a doctor, whether or not they would, could, should or shouldn't say a word. It wasn't meant for further dissection.

The initial "guess" is what I'm implying. I'm not saying give a full diagnosis but still there's no harm in a professional "opinion". And it was more meant to be a humorous comment not to be taken seriously, I was just pointing out that it's silly to assume no one here is a doctor, whether or not they would, could, should or shouldn't say a word. It wasn't meant for further dissection.

Well the thing is:
Just from what the OP stated it can be a LOT of things. Psychological stuff included.
It could be physical - partially - but there's at least 10-20 different possibilities that I am aware of that could be leading to the mentioned symptoms, and I'm by no means an expert on these issues.

It's mostly the same with people on forums describing medical symptoms and hoping for a cure delivered digitally...

If it's physical, then there's no way around proper diagnosis... guesses are guesses - and the problem with medical diagnostic guesses would simply be that there's enough bullshit to be told to scare the person badly.
And it could be something really "insignificant"...
Over the net, there's no way to even remotely safe say that it's this or that, ... what if the OP takes such an input (specific type of illness, possible treatment) serious and acts on it... what if this causes more harm than good.
Good intentions of folks who try to play net-doctor can really go wrong easily enough.

if his issues have a purely psychological background it still wouldn't hurt to get the physical side checked and ruled out.

Emily,
Such an "opinion" would be anything - but certainly not professional

Well the thing is:
Just from what the OP stated it can be a LOT of things. Psychological stuff included.
It could be physical - partially - but there's at least 10-20 different possibilities that I am aware of that could be leading to the mentioned symptoms, and I'm by no means an expert on these issues.

It's mostly the same with people on forums describing medical symptoms and hoping for a cure delivered digitally...

If it's physical, then there's no way around proper diagnosis... guesses are guesses - and the problem with medical diagnostic guesses would simply be that there's enough bullshit to be told to scare the person badly.
And it could be something really "insignificant"...
Over the net, there's no way to even remotely safe say that it's this or that, ... what if the OP takes such an input (specific type of illness, possible treatment) serious and acts on it... what if this causes more harm than good.
Good intentions of folks who try to play net-doctor can really go wrong easily enough.

if his issues have a purely psychological background it still wouldn't hurt to get the physical side checked and ruled out.

Emily,
Such an "opinion" would be anything - but certainly not professional

lol agreed, but you gotta at least admit that the very assumptive improbability that NO one on here is a medical professional is still a bit invalid no? I guess my point is that anyone on here can be in any profession, including the medical field

This is interesting. After a few years of diapering fairly often, ive noticed that anal stim doesn't work for me. At all. Used to work like a charm...I guess the magic is gone? Anyway, maybe we both need a break. From the butt..not the diapers.

lol agreed, but you gotta at least admit that the very assumptive improbability that NO one on here is a medical professional is still a bit invalid no? I guess my point is that anyone on here can be in any profession, including the medical field